摘要
本文提出分段零平均方法,引用点间加零方法,利用周期图以及自相关功率谱,对八十年代美国SMM卫星所采集的太阳总辐照度资料中1980年与1984年的两段数据做太阳振荡谱分析,对频谱进行等步长叠加证认的结果,除了得出l=0,1,2等低阶声模以外,还清楚地得出了以在对SMM资料的研究所未得到的l=3声波模式,而由相干及谱峰半宽,推出了低阶声模的相干时间即激发寿命近似为3至9天.另外,比较1980年与1984年两段数据的分析结果,发现太阳活动峰年1980年的模式频率比谷年1984年高出零点几至几个微赫兹(μHz),这意味着太阳短周期的振荡受长周期磁场变化的影响.
Two sets of solar irradiance data of the Solar Maximum Mission (SMM) spacecraft are analysed for studying solar oscillations with periodogram and auto-corre-lation spectrum. Two analysis steps are proposed for processing the SMM data, one is taking zero-average by fitting the averages of spacecraft day sections, another is inserting zeros at shorter intervals between two adjacent points in the zero-average SMM sets so that the sets may become equidistant ones. Comparing the 80's SMM modes with the 84's, a few μHz frequency drifts are found. The frequencies of 80's modes, when the Sun is at the maximum, are larger than 84's around the solar minimum. This implies that the short-period oscillations are affected by the long-period magnetic variation of the Sun.
